On the Distortion of Cirrus Logic CS431xx-Based Devices: A Comparative Review

[KDRN]

another fiio product has now implemented DRE switch

 

[pangcukaipang]

The firmware version V1.1 for HiBy FC5 with Display is available!

Changelog:
1. Added DRE switch function;
2. Added NOS option;
3. Optimized UI display;
4. Fixed several other bugs.

Connect the FC5 (with display) to your computer, download and install the upgrade tool [HiBy USB DFU Tool].
After installation, choose to upgrade locally or update online in the upgrade tool.

DFU Tool: https://www.hiby.app/usbdfu/en/
Firmware file: https://drive.google.com/drive/folders/1Xoa2kiFAQRXDXXAXWeOi6LsGsxo1fNJ5

View attachment 501075

I'm really interested with this one. But, there are basically zero review out there. Curious why they're using SGM8261-5 instead of the more common SGM8262-2.

 

[Cache]

Just wanna drop by and ask here about the NOS mode for the Moondrop Dawn Pro.
-Pressing the 2 buttons cycling the 4 filter modes until the 5th one which is the NOS mode (the light blinks twice as an indication)

I don't have some equipment to test it myself but when I test it using the CMajor file, there's no clicks but I tested it with HE400se.

I hope someone with proper testing equipment could testify this for me.

 

[KDRN]

another fiio product has now implemented DRE switch
View attachment 502300

i managed to install this today. and unfortunately the clicking is still there when ide used the CMaj test file. there is some difference where the clicking is sligtly less with the DRE off. but it is still there. which means either the DRE is not fully off , or theres something wrong in a different section of the audio stream

 

[SoySalsaPicante]

Might as well just write off all CS-DAC’d devices at this point ¯\_(ツ)_/¯

 

[markanini]

i managed to install this today. and unfortunately the clicking is still there when ide used the CMaj test file. there is some difference where the clicking is sligtly less with the DRE off. but it is still there. which means either the DRE is not fully off , or theres something wrong in a different section of the audio stream

There are clips in the OP that demonstrate much much DRE off reduces the clicking.

 

[MBO]

Luxsin X8 has DRE issues again???

No DRE off mode, no NOS mode??

 

[SoySalsaPicante]

Luxsin X8 has DRE issues again???

No DRE off mode, no NOS mode??

These CS chips are insanely popular and getting put into everything. They would rather use eight to 12 of these instead of one or two AK4499/4191 DACsets.

 

[CedarX]

These CS chips are insanely popular and getting put into everything. They would rather use eight to 12 of these instead of one or two AK4499/4191 DACsets.

Popular on the portable stuff yes... but not so much for desktop. I wonder about DRE on something like the SMSL DO200Pro reviewed by Amir: are the DRE artifacts essentially uncorrelated, minimized by the 12 CS43131 in parallel? Or, the artifacts are more threshold-related and multiple CS431xx chips in parallel shows no benefit?

 

[tccalvin]

Just wanna drop by and ask here about the NOS mode for the Moondrop Dawn Pro.

Do not use the NOS filter if you're not manually oversampling your audio files beforehand. You're going to be destroying the audio quality. A system-wide oversampling might work (setting your OS to output a much higher sample rate) but the filter is likely going to be of much worse quality than the one found in your DAC. I'd take either the DRE on mode or the DRE off mode (if available) instead.

are the DRE artifacts essentially uncorrelated, minimized by the 12 CS43131 in parallel?

No way to know for sure without testing unfortunately.

By the way, apologies if this has been done before but here's the CMaj test on my EU Apple dongle (frequencies shown from 0dBFS to -96dBFS):

This is supposed to be a different chip from the CS431XX chips but it clearly belongs to the same family.

 

[CedarX]

By the way, apologies if this has been done before but here's the CMaj test on my EU Apple dongle (frequencies shown from 0dBFS to -96dBFS):

Just to be clear: are these measurements confirming the same DRE-type artifacts on the Apple dongle?

It would be interesting to see if the CS46L41 also exhibit the issue. I believe the Apple dongle chip is a variant of that chip.

 

[Cache]

Do not use the NOS filter if you're not manually oversampling your audio files beforehand. You're going to be destroying the audio quality. A system-wide oversampling might work (setting your OS to output a much higher sample rate) but the filter is likely going to be of much worse quality than the one found in your DAC. I'd take either the DRE on mode or the DRE off mode (if available) instead.

Sorry for not doing a follow-up on my post but I just used it anyway and noticed no problem since the sheet below showed how it had no distortions if turning on NOS filter cuz it turns off DRE.

List of Devices Based On Cirrus Logic DAC Chips

docs.google.com

 

[tccalvin]

Just to be clear: are these measurements confirming the same DRE-type artifacts on the Apple dongle?

Yes, although they look slightly different from the clicks found in the CS431XX chips.

Sorry for not doing a follow-up on my post but I just used it anyway and noticed no problem since the sheet below showed how it had no distortions if turning on NOS filter cuz it turns off DRE.

It does turn off DRE, but you're trading the occasional unwanted distortion for omnipresent ultrasonic noise and high-frequency roll-off. Reconstruction filters are essential in a DAC. If you're going to essentially turn them off by picking the NOS filter, you need to filter your content elsewhere. Don't get me wrong, it's not like the NOS output will be unlistenable, but the objective measurable performance will be undistinguishable from a 1980s' DAC. I wouldn't recommend it.

If you go back and forth between OS (I recommend fast roll-off) and NOS filters, you'll easily notice that the OS option sounds brighter and more detailed (assuming you're not oversampling your content).

If you still prefer the NOS option, well... more power to you, I guess!

 

[jkim]

Just to be clear: are these measurements confirming the same DRE-type artifacts on the Apple dongle?

It would be interesting to see if the CS46L41 also exhibit the issue. I believe the Apple dongle chip is a variant of that chip.

IIRC someone else tested and reported DRE distortion from the Apple dongle, too. In fact, I believe ALL Cirrus Logic OEM DAC chips feature DRE and exhibit associated distortion. The distortion behavior may differ (e.g., attenuation range in which DRE is activated) from one chip to another, though.

 

[Cache]

It does turn off DRE, but you're trading the occasional unwanted distortion for omnipresent ultrasonic noise and high-frequency roll-off. Reconstruction filters are essential in a DAC. If you're going to essentially turn them off by picking the NOS filter, you need to filter your content elsewhere. Don't get me wrong, it's not like the NOS output will be unlistenable, but the objective measurable performance will be undistinguishable from a 1980s' DAC. I wouldn't recommend it.

If you go back and forth between OS (I recommend fast roll-off) and NOS filters, you'll easily notice that the OS option sounds brighter and more detailed (assuming you're not oversampling your content).

If you still prefer the NOS option, well... more power to you, I guess!

So if I were to use the NOS filter, I would need like to increase to like 32bit 384kHz and that is still gonna be like worse than me using the Fast Roll-off Low Latency (default filter setting)?

 

[tccalvin]

So if I were to use the NOS filter, I would need like to increase to like 32bit 384kHz and that is still gonna be like worse than me using the Fast Roll-off Low Latency (default filter setting)?

An OS-wide resampling is likely going to be worse than a dedicated DAC's. If you listen to local audio files on your device, though, you can resample them using a high-quality algorithm like Audacity's SoX and you're good to go. I mainly listen to streamed content so that's not an option for me.

In order from best quality to worst quality (in my opinion):

[Good DAC OS filter implementation] = [Manually (offline) resampled files with high-quality filter + NOS DAC] > DRE off > DRE on > OS-wide resampling > NOS or no filter

One may disagree on what trade-off is preferable (distortion vs SINAD vs clicks vs ultrasonics) but the first two options are the ones that give the most objectively accurate result.

EDIT: By "OS-wide" I mean Operating-System-wide. OS filter is an Over-Sampling filter. Sorry for the acronym confusion.

 

[IsaacOscar]

@jkim I've been looking into getting a FIO DAC, so I've made a table of all the Fiio products I could find on the Fiio website that contain the CS43131 or CS43198, and whether there's a firmware update with DRE switch:

Product	Latest Update	DRE Update?
Retro Nano	5/01/2026	Added DRE control switch
K11	5/11/2025
KA5	22/08/2025	Optimized DAC DRE parameters
Melody	11/08/2025	Added DRE control switch
KA15	1/08/2025	Added DRE control switch
KA13	23/07/2025
BTR13	8/11/2024
KA2	30/09/2024
KA11	6/03/2024
Q11	28/04/2023
DM13	4/06/2025
KB3	1/04/2024
Echo Mini	21/08/2025	Optimized DAC DRE parameters
M21	29/08/2025	Added DAC DRE function switch
JM21	26/09/2025	Added DAC DRE function switch

(note the M3 contains the CS42L51, and the X3II contains the CS4398, which I'm assuming are not problematic)


So if someone comes along later, they can click the above links to see if a DRE fix has been published since I made this post.

 

[SoySalsaPicante]

@jkim I've been looking into getting a FIO DAC, so I've made a table of all the ones I could find on the Fiio website that use a Cirus chip (CS43131 or CS43198) and whether there's a firmware update with DRE switch:

Product	Latest Update	Added DRE Control Switch?
Retro Nano	5/01/2026	yes
K11	5/11/2025
KA5	22/08/2025	maybe (it says "optimized DAC DRE parameters")
Melody	11/08/2025	yes
KA15	1/08/2025	yes
KA13	23/07/2025
BTR13	8/11/2024
KA2	30/09/2024
KA11	6/03/2024
Q11	28/04/2023

So if someone comes along later, they can click the above links to see if a DRE fix has been published since I made this post.

Note: I only checked DAC's & AMPS (so I didn't check other things that might have a DAC chip inside, e.g. a DAP or bluetooth headphone)

FiiO M21 and JM21 both received firmware updates to add DRE disable.

 

[IsaacOscar]

FiiO M21 and JM21 both received firmware updates to add DRE disable.

Thanks, I've now decided to check every Fiio product that might contain a DAC, so hopefully my table is now complete.

 

[IsaacOscar]

I tried to play the CMajor files, but even with IEM's at maximum volume I couldn't hear a difference between any of the files, or through my DAC (the Xiaomi Hifi Pro) with -15 dbFS.
EDIT: I was doing my tests wrong, my DAC does indeed have the problem.

So I tried to use Room EQ Wizard and recorded the output of my DAC through my motherboards line-in jack, and here are my results.:

So I think even though my DAC apparently has a CS43131 in it, which I bought like 6 years ago, and have never updated the firmware, it doesn't have the cirrus hump issue?

@jkim did I do this correctly? (I've never used REW before so I was thoroughly confused; I used the "All SPL" view as that was that one showed the most obvious difference between the "Original_CMaj" and "Tanchjim_Stargate2_JCally_JM20Pro_CMaj" files).

EDIT: I've done a level sweep with this multitone program I found, and definitely no hump:

And here's a spectrogram of the C Major test, with the gain set to -15db